Integrated CMOS/MEMS microphone die components

Abstract

A die is manufactured using complementary metal-oxide semiconductor (CMOS) techniques to create transistors, electrical pathways, and microelectromechanical system (MEMS) structures. The MEMS structures include springs, plates, mechanical stops, and structural supports, which can be combined to form complex MEMS structures including microphones, pressure sensors, accelerometers, resonators, gyroscopes, and the like.

What is claimed is: 
     
       1. A diaphragm for a CMOS MEMS capacitive microphone die comprising:
 a first substantially planar metallic layer having a top surface and a bottom surface, where a portion along the perimeter of the first layer defines a first edge of the first layer; 
 a second substantially planar metallic layer having a top surface and a bottom surface, where
 a portion along the perimeter of the second layer defines a first edge of the second layer, 
 the first edge of the second layer is substantially the same size and shape as the first edge of the first layer, and 
 the first edge of the second layer is substantially aligned vertically with the first edge of the first layer, except that the first edge of the first layer extends horizontally, with respect to the geometric horizontal center of the first layer, beyond the first edge of the second layer; and 
 
 a first plurality of vias between the first and second layers, the vias attached to the top surface of the first layer and the bottom surface of the second layer. 
 
     
     
       2. The diaphragm of  claim 1 , where:
 a portion along the perimeter of the first layer defines a second edge of the first layer, the second edge of the first layer being a different portion than the first edge of the first layer; 
 a portion along the perimeter of the second layer defines a second edge of the second layer, the second edge of the second layer being a different portion than the first edge of the second layer; 
 the second edge of the second layer is substantially the same size and shape as the second edge of the first layer; and 
 the second edge of the second layer is substantially vertically aligned with the second edge of the first layer, except that the second edge of the second layer extends horizontally, with respect to the geometric horizontal center of the first layer, beyond the second edge of the first layer. 
 
     
     
       3. The diaphragm of  claim 1 , further comprising:
 a second plurality of vias extending upwards from the first layer along its first edge where the first edge of the first layer extends beyond the first edge of the second layer. 
 
     
     
       4. The diaphragm of  claim 1 , further comprising:
 a third plurality of vias extending downwards from the second layer along its second edge where the second edge of the second layer extends beyond the second edge of the first layer. 
 
     
     
       5. The diaphragm of  claim 1 , where:
 the first layer being substantially solid from side to side; and 
 the second layer having a plurality of openings between the top surface and bottom surface.